Buick Regal: DTC B0081 (SDM)

Diagnostic Instructions

• Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
• Review Strategy Based Diagnosis for an overview of the diagnostic approach.
• Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptors

DTC B0081 00

Passenger Presence Module Malfunction

DTC B0081 3A

Passenger Presence Module Incorrect Component Installed

DTC B0081 71

Passenger Presence Module Invalid Serial Data Received

Circuit/System Description

When the ignition is turned ON, the Inflatable Restraint Sensing and Diagnostic Module and the Passenger Presence Module perform tests to diagnose critical malfunctions. Upon a successful power-up mode the Inflatable Restraint Sensing and Diagnostic Module will illuminate both PASSENGER AIRBAG ON/OFF indicators located in the overhead center console. If the Inflatable Restraint Sensing and Diagnostic Module detects a fault in the Passenger Presence Module, it may disable the front passenger air bag deployment loop, set DTC B0081 00 or DTC B0081 3A and illuminate the AIRBAG indicator.

Conditions for Running the DTC

Ignition voltage is between 9 - 16 V.

Conditions for Setting the DTC

B0081 00

The Inflatable Restraint Sensing and Diagnostic Module has received a fault present message from the Passenger Presence Module.

B0081 3A

The Inflatable Restraint Sensing and Diagnostic Module has received a message from the Passenger Presence Module indicating a vehicle to Passenger Presence Module mismatch.

B0081 71

The Inflatable Restraint Sensing and Diagnostic Module sets this DTC when the Inflatable Restraint Sensing and Diagnostic Module has received invalid serial data from the Passenger Presence Module.

Action Taken When the DTC Sets

• The Inflatable Restraint Sensing and Diagnostic Module requests the instrument cluster to illuminate the AIR BAG indicator.
• The passenger instrument panel air bag deployment loop will be disabled.

Conditions for Clearing the DTC

• The condition for setting the DTC no longer exists.
• A history DTC will clear once 100 malfunction-free ignition cycles have occurred.

Diagnostic Aids

• If either the Inflatable Restraint Sensing and Diagnostic Module or Passenger Presence Module were replaced verify that the correct part numbers were used for the vehicle application.
• If this DTC is set as either current or history it may have been caused by an electronic device. If an electronic device (Computers, MP3 Players, Cell Phones, Diagnostic Scan Tool, Power Inverter, etc.) was placed on the passenger seat the Passenger Presence Module may command the passenger air bag indicator to turn on and/or command the passenger seat belt indicator to turn on. Make sure there are no objects on the passenger seat and clear the DTCs. If this DTC resets then perform this diagnostic. If the DTC does not reset there is no further work needed on the passenger presence system.
• If this DTC is set as either current or history it may have been caused by an aftermarket seat heater. The aftermarket seat heater may command the passenger air bag indicator to turn on and/or command the passenger seat belt indicator to turn on. Remove the aftermarket seat heater from the passenger seat and clear the DTCs. If this DTC resets then perform this diagnostic. If the DTC does not reset there is no further work needed on the passenger presence system.

Reference Information

Schematic Reference

SIR Wiring Schematics

Connector End View Reference

Component Connector End View Index

Description and Operation

Supplemental Inflatable Restraint System Description and Operation

Electrical Information Reference

• Circuit Testing
• Testing for Intermittent Conditions and Poor Connections
• Connector Repairs
• Wiring Repairs

Scan Tool Reference

Refer to Control Module References for scan tool information.

Circuit/System Verification

NOTE: Both the Inflatable Restraint Sensing and Diagnostic Module and Passenger Presence Module set DTC B0081 but with different symptom bytes. Therefore it is important to identify which module has set the DTC B0081. Use the symptom bytes as a way of identify the correct module to diagnose. Use the table below in identifying specific module DTC B0081 application and symptom byte that sets with it.

1. Verify that DTC B1001 is not set in the Inflatable Restraint Sensing and Diagnostic Module.

• If DTC B1001 is set in the Inflatable Restraint Sensing and Diagnostic Module

Refer to DTC B1001 (Passenger Presence System) or DTC B1001 (Inflatable Restraint Sensing and Diagnostic Module).

• Go to next step: If DTC B1001 does not set in the Inflatable Restraint Sensing and Diagnostic Module

2. Verify that DTC B0074, B101D, or B101E is not set in the Passenger Presence Module.

• If any of these DTCs are set in the Passenger Presence Module, refer to Diagnostic Trouble Code (DTC) List - Vehicle
• Go to next step: If none of these DTCs are set in the Passenger Presence Module

NOTE: The Inflatable Restraint Sensing and Diagnostic Module sets a redundant B0081 00 DTC when the Passenger Presence Module sets a DTC B0081 11 or B0081 42.

3. Verify that DTC B0081 00 is not set in the Inflatable Restraint Sensing and Diagnostic Module

• If DTC B0081 00 is set

Replace the K85 Passenger Presence Module.

• Go to next step: If DTC B0081 00 is not set

NOTE: The Inflatable Restraint Sensing and Diagnostic Module sets a B0081 3A when an incorrect Passenger Presence Module is installed.

4. Verify that DTC B0081 3A is not set in the Inflatable Restraint Sensing and Diagnostic Module.

• If DTC B0081 3A is set

Replace the K85 Passenger Presence Module.

• Go to next step: If DTC B0081 3A is not set

5. Verify that DTC B0081 71 is not set in the Inflatable Restraint Sensing and Diagnostic Module.

• If DTC B0081 71 is set

Replace the B60 Passenger Presence Sensor.

• Go to next step: If DTC B0081 71 is not set

6. All OK.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the repair.

Refer to Control Module References for Passenger Presence Module and Inflatable Restraint Sensing and Diagnostic Module replacement, programming and setup.

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